Using Serviceguard Extension for RAC Version A.11.20 - (August 2011)

configured to automatically fail over from the original node to an adoptive node. When the original
node is restored, the listener package automatically fails back to the original node.
In the listener package ASCII configuration file, the FAILBACK_POLICY is set to AUTOMATIC.
The SUBNET is a set of monitored subnets. The package can be set to automatically startup with
the AUTO_RUN setting.
Each RAC instance can be configured to be registered with listeners that are assigned to handle
client connections. The listener package script is configured to add the package IP address and
start the listener on the node.
For example, on a two-node cluster with one database, each node can have one RAC instance
and one listener package. Oracle clients can be configured to connect to either package IP address
(or corresponding hostname) using Oracle Net Services. When a node failure occurs, existing
client connection to the package IP address will be reset after the listener package fails over and
adds the package IP address. For subsequent connections for clients configured with basic failover,
clients would connect to the next available listener package's IP address and listener.
Node Failure
RAC cluster configuration is designed so that in the event of a node failure, another node with a
separate instance of Oracle can continue processing transactions. Figure 3 shows a typical cluster
with instances running on both nodes.
Figure 3 Before Node Failure
Figure 4 shows the condition where node 1 has failed and Package 1 has been transferred to
node 2. Oracle instance 1 is no longer operating, but it does not fail over to node 2. The IP address
for package 1 was transferred to node 2 along with the package. Package 1 continues to be
available and is now running on node 2. Also, node 2 can now access both the Package 1 disk
and Package 2 disk. Oracle instance 2 now handles all database access, since instance 1 has
gone down.
Node Failure 19